The nervous systems Flashcards
CNS: central nervous system
CNS make up the brain and spinal cord
1) Somatic nervous system - Controls conscious activities (e.g. thinking)
2) Sympathetic nervous system gets the body ready for action . FIGHT OR FLIGHT.
- Sympathetic neurones release the neurotransmitters called noradrenaline.
PNS: Peripheral nervous system
PNS is made up of the nerves that connect the CNS to the rest of the body
1) Autonomic nervous system- controls the unconscious activities such as digestion.
2) Parasympathetic nervous system CALMS the body down . “REST and DIGEST system”
- Parasympathetic neurones release the neurotransmitters acetylcholine.
what are the 5 different parts of the brain?
1) Hypothalamus- controls body temperature
2) Cerebrum- Involved in vision, hearing, learning, thinking
3) pituitary gland- Controlled by hypothalamus, it releases hormones and stimulates other glands.
4) Medulla oblongata- Controls breathing rate and heart rate
5) Cerebellum- Muscle coordination , posture and balance.
What is a reflex?
Where your body responds to a stimuli without making a conscious decision to respond.
- reflexes are so fast that you can avoid damage.
The blinking reflex:
1) Nerves in the cornea are stimulated by touch
2) Nerve impulses travel along sensory neurones to the relay neurones in the CNS
2) Impulses are passed on from the relay neurone to the motor neurone
3) Motor neurones send impulses to the effectors (orbicularis oculi muscles), causing them to contract which causes the eyelids to close to prevent eyes from being damaged
Knee jerk reflex:
- This to maintain posture and balance
1) Stretch receptors in the quadricep muscle detect that the muscle is being stretched.
2) Nerve impulse is passed along the sensory neurone , and the impulse is passed onto a motor neurone in the spinal cord
3) The motor neurones pass on the nerve impulses to the effectors ( quadricep muscles) causing them to contract so the lower leg moves forward quickly.
